Triple-valve mechanism



(HoModel.)

G. W. HAYDEN'.

TRIPLE VALVE MECHANISM.

UNITED STATES PATENT OEEicE.

GEORGE IV. IIAYDEN, OF OAK PARK, ASSIGNOR TO THE CRANE COMPANY, OF CHICAGO, ILLINOIS.

TRIPLE-VALVE MECHANISM.

SPECIFICATION forming part of Letters Patent No. 556,886, dated March 24, 1896.

Application filed March 21, 1895. Serial No, 542,642. (No model.)

To all whom t may concern: tion is made, resulting in a total failure to re- Bc it known that I, GEORGE WV. IIAYDEN, lease. a citizen of the United States, residing at Oak In my invention I aim to obvia-te these dif- Park, Cook county, Illinois, have invented cericulties by providing another piston to oper- 55 5 tain new and useful Improvements in Tripleate the small supplemental valve, which is Valve Mechanism for Automatic Air-Brakes, separate from the piston which operates the of which the following is a specification. main emergency-valve. rlhis enables me to My invention relates particularly to the so change the other parts and the arrangeclass of triple valves shown in Patents No. ment of the devices as a whole as to make 6o Io 496,651, to James T. Hayden, and No. 504,139, the apparatus in gen eral much more effective to Paul Synnestvedt, and is in the nature ci and satisfactory. an improvement on the devices therein set Reference being had to the accompanying forth. drawings, Figure l is a sectional view of my In the constructions referred to a single pisvalve, taken on the broken line A A of Fig. 2. 65 I5 ton is used to operate both the emergency- Fig. 2 is a sectional view taken on the line B valve proper and the small supplemental B of Fig. l.

valve which performs the function of exhaust- The train pipe, auxiliary reservoir, and ing the pressure from one side of the emerbrake-cylinder connections are made as usual gency-piston in quick-action applications. and are marked on Fig. 2. 7o

2o Such a design requires that there be a slight The members for performing the ordinary amount of lost motion between the emerfunctions of graduation and release are subge-ncy-valve proper and its piston, so the small stantially identical with the corresponding supplemental valve may open prior to the devices shown in the second of the patents movement of the large valve. The sliding above mentioned, and not forming any part 7 5 2 5 t between the stem of the large valve and the of my present invention need no further menemergency-piston has to be areasona-bly close tion here. one, or the leakage through would destroy, in The mechanism provided for the purpose whole or in part, the operative effect of the oi' performing the function of quick action is pressure, in view of which such construction contained in the lower part of the main cas- 8o 3o is very sensitive to interference caused by ing l, and consists in general of an emergencylodgment in and around the parts of dirt, ice, valve 2, controlling an opening 3, an emeror oily gum. These difficulties are further gency-piston a, working in a bushing 5, a supaggravated by the use of awide or trunk pisplemental Valve 6, controlling an exhaustton, which, because of the extent of its bearport from the left side of the piston 4, a sup- S5 35 ing-surface, is particularly liable to become pleniental piston 7 for operating said supplestuck from such lodgment of dirt around its mental valve, and a check-valve 8, similar to circumference. those commonly used, for preventing the re- Another difficulty which has been encounturn of the brake-cylinder pressure to the tered in the use of the constructions shown in train-pipe in case of rupture of the latter. 9o

4c the patents above referred to arises from the As the course of some of the passages is smallness of the stem of the supplemental very irregular and difficult to illustrate, it valve, (necessitated by the fact that it must may here be expedient to say that (the parts operate inside of the stem of the emergencybeing in the position shown) air after entervalve proper,) the violence of the action in ing at the train-pipe connection at a passes in 95 45 cases of emergency sometimes breaking the two directions-first, upward through the passtem or upsetting it at the point where the sage b to the cavity c, around the bushing 5 valve seats, so as to prevent its withdrawal. and through the port d, which is just uncov- The above-mentioned defects may result ered by the left edge of the piston 4, filling either in so disabling the apparatus that no the chamberaand, second,downward through 10c 5o emergency action is possible, or else in causthe passage f to the under side of the piston ing the valve to stick open after an applica- 7, around the piston by means of the by-pass port r, and through the emergency-valve chamber 7L and the passage i to the left side of the main piston. The port 3 opens into the cavity j, which is at all times in open communication with the brake-cylinder through the passage 7c (shown in dotted lines in Fig. l)y and the opening l.

The parts as shown are in the release or normal position7 in which the brake-cylinder is in open communication with the atmosl of pressure on the opposite sides of the pistons phere. In this position it is to be noted that the emergency-valve 2 and the supplemental Valve 6 (both of which control openings leading to the brake-cylinder) are held shut by train-pipe pressure assisted by a spring and that the emergency-piston et and the supplemental piston are both in a state of equilibrium, each having train-pipe pressure on both sides.

To apply the brakes in service stops, a reduction is made in train-pipe pressure. causes the: air to the left of the main piston to flow'back through passage i', chamber h, and by-pass port g to the train-pipe, the reduction having been made gradually, drawing the main piston back Without disturbing.

the equilibrium of either the emergency-piston 4 orthe supplemental piston 7.

Ona sudden and extreme reduction, how'- ever, in the train-pipe pressure the air to the left of the main piston and in the chamber 7i, flows back more rapidly and, the by-pass g being small, exerts a downward pressure on This f the supplemental piston 77,y draws the valve '5 away from its seat, and thus vents the pressure on the left side of the emergency-piston 4L to the brake-cylinder. The air to the right of the piston then moves it to the left and by opening the emergency-Valve 2 and uncovering the circumferential ports CZ in the bushing 5 Vents the remainder of the train-pipe pressure to the brake-oylinder.

As soon as leakage restores the equilibrium 7 and 4, the parts are returned again to normal position by their respective springs.

Having thus described my invention, what I claim as new; and desire to secure by Letters Patent, is-` ln emergency devices for triple-Valve mechanism7 the combination of: a chamber-or easingha'ving a port leading from a train-pipe to a brake-cylinder: an emergency-Valve for controlling said port: a piston for operating said emergency-Valve: a supplemental port o or passage leading fromk one side of said emergency-piston to the brake-cylinder: a supplemental val-ve for controlling such supplemental passage: anda separate piston foreperating said supplemental valve: substantially as described.

GEORGE W. HAYDEN.

liitnesses zr CHAs. A. G. WAGMAN, E. E. GRANQUIST. 

